AB0916 Efficacy and predictive factors of clinical response to tnf inhibitors in patients with axial and peripheral psoriatic arthritis

Abstract

BackgroundPatients with psoriatic arthritis (PsA) may have predominant axial (axPsA) or peripheral (pPsA) manifestations. The development of TNF inhibitors (TNFi) has changed the course of PsA. However, most published data is focused on pPsA but almost no data is available for TNFi response in axPsA.Objectivesto analyse the efficacy and the predictive factors of clinical response in patients with axPsA and pPsA starting treatment with TNFi in clinical practice.MethodsAn observational study analysing data from a prospective cohort including 93 patients (pts) with axPsA or pPsA treated with TNFi from 2002–2018 was conducted. Demographic information, disease activity indexes (ASDAS for axPsA and DAS28 for pPsA) and laboratory tests were collected before starting TNFi (baseline visit) and 6 months later (6 m visit). At 6 m, the percentage of pts achieving inactive disease (ASDAS <1.3) for axPsA or remission (DAS28 <2.6) for pPsA as well as the percentage of pts achieving clinical improvement (defined as ASDAS-clinically important improvement=delta-ASDAS>1.1 or delta-DAS28 >1.2) were determined. Baseline predictor factors of inactive disease/remission and clinical improvement at 6 m were identified using a univariable and multivariable binary regression models adjusted for confounder factors.ResultsOut of 93 included pts, 45 pts had predominant axPsA and 48 pPsA. Administered TNFi was etanercept for most pts (42%), infliximab in 29%, adalimumab in 22% and golimumab in 7%. Baseline characteristics are shown in table 1. Male sex was more frequent in axPsA vs pPsA (62% vs 42%; p=0.04, respectively). In axPsA, 55% clinically improved and 32% pts achieved inactive disease. After multivariable analysis, male gender (OR 25.8, p=0.01) and higher baseline ASDAS (OR 6.3, p=0.01) were associated as independent predictors of clinical improvement at 6 m. Also, male gender (OR 15.7, p=0.03) and lower BMI (OR 0.7, p=0.03) were associated as independent predictor factors for achieving inactive disease. In pPsA, 48% pts clinically improved and 33% pts were on remission at 6 m. The percentage of pts on remission tended to be higher in males than females (47% vs 20%; p=0.08, respectively). However, after running the regression analyses, none of the baseline predictor factors was significantly associated neither with clinical improvement nor with remission in patients with pPsA.Abstract AB0916 – Table 1 Total n=93p-value axPsA n=45pPsA n=48 Male, n (%)28 (62%)20 (42%)0.04BMI, Mean (SD)27.4 (5.5)26.4 (5.5)0.3Age (years), mean (SD)56 (12.9)60 (14.2)0.2Smokers, n (%)18 (41.9%)15 (31.9%)0.3Disease duration (years), mean (SD)19 (10.8)18 (8.4)0.6HLA B27, n/N (%)8/22 (36%)-RF, n/N (%)-3/44 (6.8%)ACPA, n/N (%)-0/45csDMARDs, n (%)25 (68%)24 (68%)0.9bASDAS, mean (SD)3.1 (1.2)-bDAS28, mean (SD)-4.7 (1,3)bCRP mg/L, mean (SD)13.2 (14.7)10.5 (15.3)0.3bESR, mean (SD)26.3 (20.9)27.8 (19.8)0.5ConclusionsIn clinical practice, 1 out of 3 pts with PsA is on remission 6 m after initiating a TNFi, and 1 out of 2 clinically improve; both proportions are similar...